Dometic DuoTherm issues

[nastonius]

Howdy y’all.

Got a funny issue with our AC. Recently, it was not cycling correctly: the tstat would engage the fan motor, but the compressor would not kick on. It would repeat this cycle a few times before we would manually shut the system down and restart it. It would then work properly for a while. I did some reading here and saw I would probably need a new control box.

But we just had something strange happen a few times. The tstat sent the signal to turn the system off, and the fan would shut off, but not the compressor, so a few seconds later, the fan would kick back on.

Is this the “bad relay in the control box” problem, with potentially a relay that is stuck closed (therefor not kicking the compressor off)? When googling the part number, it looks like it’s been superseded to 3316230.700 now. Am I headed in the right direction?

My control box has 3313191.000 as a part number, and I have the black touch-style digital tstat.

Thanks in advance for any help!

 

[Hollandt]

Howdy y’all.

Got a funny issue with our AC. Recently, it was not cycling correctly: the tstat would engage the fan motor, but the compressor would not kick on. It would repeat this cycle a few times before we would manually shut the system down and restart it. It would then work properly for a while. I did some reading here and saw I would probably need a new control box.

But we just had something strange happen a few times. The tstat sent the signal to turn the system off, and the fan would shut off, but not the compressor, so a few seconds later, the fan would kick back on.

Is this the “bad relay in the control box” problem, with potentially a relay that is stuck closed (therefor not kicking the compressor off)? When googling the part number, it looks like it’s been superseded to 3316230.700 now. Am I headed in the right direction?

My control box has 3313191.000 as a part number, and I have the black touch-style digital tstat.

Thanks in advance for any help!

If you have the fan in automatic it will switch between high speed and low speed depending how far above set point the temp is. When it switches the fan will shut down completely while switching. The compressor continues to run. I don't remember the time but it will shut down but it is around 5 to 10 sec while switching.

 

[nastonius]

That is something I hadn’t even thought about (or known about) the unit doing. That sounds pretty close to what is happening. I’ll double check what my fan is set to to make sure that’s what it is.

Thanks so much for the insight!